Gear lubricant



Jan. 20, 1931. s. D. WHITE ET AL 1,789,614

'GEAR LUBRICANT Filed Aug. 18, 1928 o A. o O 0 INVENToRs 5mn/ey zz. Wfl/fe ATTORNEYS Jan. 20, 193i. l s. D. WHITE ET AL I 1,789,691

'GEAR LUBRICANT l Filed Aug. 18, 1928 ATTORNEYS v o lubricant for use in Patented Jan. 20, 1931 y uru'rlazn STATES STANLEY D. WHITE AND CARL L; INOPF,

crans. n mININe coMrnNY, or NEW Yoan, N.

'Y am LUBnIcANr applicati lured August 1s, 192s. serial N6. 300,538.

This invention relates to-improvements in gear lubricants intended particularly for use in transmissions and diiferentials in automo- .bile machinery. The invention provides an 5 improved gear lubricant of special value in such application.` yThis improved gear lubricant has" a number of vimportant advantages, among the more important of which is the ability vof the new lubricant to operate satisfactorily over a wide range ottemperatures` v The invention also includes, in addition to the improved lubricant product, certain improvements in manufacturing methods. Onev of the lmost ldiiilci'llt lubrication problems presented in the operation .of automobile .machinery is the lubrication of transmissions and 'differentials In the early days of the. automobile, the automobile was'not usually expected to be in service twelve months of ,the year; automotive en.

gineeringv had not progressed this far, the closed b dy had not been developed to its present stage, and with but few exceptions highways were noty passable for the automo' bile but for a limited seas As a consequence, this loblem of lubrication was then largely con ed to meeting conditionsof moderate and hot weather. As mechanical and body design progressed, making the automobile more and more useful through all twelve months of the year, a number o f makeshift lubricants were employed, for the lubrication of'transmissions and differentials to meet the increasing range of temperatures encountered in automobile operation, but hitherto the bestv solution o the roblem hasbeen to use one' type of lubricant 1n hot weather and another type of lubricant in cold weather. The disadvantages ofthe thus imposed requirement for manufacture and. distribution oftwo types of lubricants for thesame lpurpose areobvious. In addition to multiplication of manufacturing -operations and' duplicationy of stocks, this situation has'involved a tremendous annual exi penditure 'for repairs and replacement due to aulty or improper lubrication. I

For operation throughout the year, a gea t 1e' transmissions and .diiferentials of automobilemachinery must, essentially, retain-its lubricating characteristics at temperatures as high as 100 F. or y somewhat higher and at temperatures asv low as 0 F. or somewhat lower and 'throughout the intervening range and must also satisfy several other, less fundamental but nevertheless important, requirements. For example, the burden of lubrication in dilerentials is usually higher than in transmissions which would simplify the problem with respect to transmissions except thatreasonable ease of shiftin transmission gears must also be maintained throughout the range of operat-` ing temperatures.

The improved gear `ent (invention consists essentially of an oxidized. blend, substantially lfree from water, of light lubricating oil, heavy ilux oil andA ysodium soaps of pletroleum acids, the latter articularly in t e form of caustic bottoms lubricant of the pres-,j

'om the distillation of lubricating oils-from Gulf Coast type stocks over caustic soda, this A, blend in aparticularly advanta eous form of the invention having -a MacMic ael viscosityv of 55-100 or better 70-[85 poises at 100 F., a Knopf viscidity not exceeding 12 ounces at 0. F. and a Knopf adhesiveness not exceeding 7 5 ounces at 0 F. The'MacMichael viscosity and the Knopf vviscidity are more im- -portant than the Knopfadhesiveness. A petroleum lubricant blend'having a `viscosity, viscidty` over the temperature range just speiied'is apparently. entirely novel'. The improved lubricant of the invention consists .generally about one-half of light lubricating oil, about onefthir'd of yheavy 'flux oil and about onesixth of'caustic bottoms, the blend being partally oxidized as byair blowing. The improved lubricant of the invention may comj -prise, `advantageously, a blend (i5-88% or etter 83-85% of a m1xtu`re\of light lubricating oil and heavy flux oil in ro ortions such that thecomposite has a ay olt'viscosity vof 55-62 seconds at 210 F. and 15a-.35% or,

better 15`17% of caustic bottoms' of thevtype lmentioned above having a Knopf viscidity of15-35 or better 15-25 ounces at 100 F.,

the blend being blown with airfat elevated'/On and adhesiveness just specified temperature, 250-300 F., until the Mac- Michael viscosity at 100 F. of the' resulting composite approximates 55-100 or better 70-85 poises and the Knopf viscidity 4-12 ounces at F.

The improved gear-lubricant of the present invention functions properly over a wide temperature range and is satisfactory for use throughout theiyear, in winter as well as in summer. Its use eliminates, for the operlatorfof automobile machinery, any necessity for changing the` transmission and differ- .entiallubricant with change of season and,

. for the' manufacture and distributor, the

makin and handling of a pluralitv of lubri-vk cants or the same purpose. It 'has a viscidity low enough to permit easy shifting of transmission gears, even at temperatures as low as 0 F. or lower. It is suiciently adhesive to feed properly in gear sets and maintain effective lubricating films, particularly in differentials, even at high temperatures,v

up to 10G-120 F. or higher. `It has a low y drag resistance thusginvolving' a minimum of ower loss and promoting easylstarting. It oes not channel, permitting gears to run dry, even at temperatures as low as 0 F. or

` lower. It is non-corrosive. It has suicient body .w

to Yminimize any leakage from gear houslngs, even at high temperatures.

,- For the determination of viscosities at temperatures in the neighborhood of 100 F.,

of this type of lubricant, the standard Mao- Michael torsion viscosimeter is satisfactory. For the determination of viscidity and adhesiveness at low temperatures, `the usual types of instruments are 'not satisfactory. The Knopf viscidometer and the Knopf adherometer are reliably accurate` in the testing of this type of lubricant-at low temperatures. .The foregoing therefore refers to these modes of measurment.i These twolast mentioned instruments are illustrated, diagrammatically, in the -accompanyin drawings and are described in more detai in Letters Patent No. 1,748,512 and No. 1,748,513, is-

sued to Sinclair Refining Company, Feb'- ruary 25, 1930, on applications of ,one of us, Carl L. Knopf. g

A standard automobile transmission and a standard automobile differential/with `openlings cutin the gear housings to permitob servation, arranged within g a thermostat chamber and connected with an elect'ric motor and pon brake,.to be driven ata propriate spee s under appropriateloa,r s',

`were "used 1n the development ,ofjthe iinxA e proved lubricant of this invention. [This apparatus permitted the directfobservation ofthe action of the lubricants studied over-'fa wide range of temperatures.. fstroboscope was also used iny connection with this .appar ratus to permit the study of formation maintenanceof lubricant films in the-'g'ear sets by direct observation. f2',

Tested in the apparatus just mentioned,

more immediately apparent than in actual use. Without exception,vthose usual lubricants which were satisfactory at high temperature were deficient at low temperature and vice versa; for example, lubricants'which maintained satisfactory lubricating ilms and Athe ldeficiencies of the `usual lubricants were were of good body at high temperature be came so viscid at low temperature as tochannel or .t9 make the. shifting ofrtransmission gears dilicultlif not impossible; While those suiiiciently fluid at low temperature failed to provide proper lubrication at high temperature-:because of lack of body or suiicient ad- .hesiveness to feed in the gear sets.

of 20-7 5 ounces or'not exceeding 7 5 ounces at 0 F. are of special value'ffor" this purpose. This invention provides a petroleum blendlwu'- 'bricant satisying these requirements, the rgquirements o actual service.

e manufacture of this gearlubricantgis, illustrated by the followin 'example :Light A glear lubricantembodying the irl-venti@ ff-.f and t Gulf Coast lubricating oil A'aving aSaybolt viscosity of v seconds at 100 F. is thoroughly l ended with av heavy Gulf .Coast flux oil having a Saybolt viscos1ty of 1,00045,000

seconds at 210 F.'in roportions to produce a baseblend having a ayboltviscosity lof' 5.5M-` 62 seconds, 57 seconds for example, at 210 This basefblen'd isthen' heated tof a tempera? f" fore'xample, and causticI ottoms from the re'- y distillation o ffGulf Coast lubricating oils. over caustic' soda preheated yto 'a correspondin tem erat'ure are then gradually blen ed witv thel ase blend, ','Thoroughjmixing is essen'- tial., Using caustic bottoms having a Knopf usually required'. If fthe;y viscidity of-L the austiqlbottoms':'is'less 'a somewhat increased Machdlichaelviscositybf poiseslatlOD vFfa'nd 'a Kn'opfLviscidityofapproximately 10 'ounces atQ? The temperature'during this operation'is best4 limited not to exceed F.

proportionfof .caustic bottoms 'is .i1'sed, ami` 'vice'.l versagf The.fCDlIlPSite s'toelrffis. then Y "withjai utilfthervesulting. product has a -3000 F. for 2 -3 hours or longer. thorough mixing to prevent excessive oxidation. The period of oxidation usually approximates 4-8 hours. The air applied during the oxidation operation is with advantage previously dried, for example by passage through a calcium chloride drier. If water is present in the base blend prior to admixture of the caustic bottoms, it -is` also advantageous to blow this base blend with dried air to dehydrate it rior to admixture of the' caustic bottoms. The finished product is then run to storage. The finished product is also, with advantage, stored in an atmosphere substantially free from water. Cooling of the finished product is with advantage limited to a slow rate.

If the oxidized composite, when tested, is insufficiently viscous or viscid, the viscosity and viscidity are increased by prolonging the oxidizing operation. If the viscosity and viscidity of the composite product, when tested, are too high, the viscosity and viscidity can be reduced within a limited range by the addition of incrementsv of the base blend. When the base blend isadded to the composite at this stage of the manufacturing operation, the resulting composite blend is best held at a temperature in the neighborhood of Again, is essential.

A reduction 1n viscosity and viscidity of the lubricant product usually takes place during storage, a drop in a MacMichael viscosity from to 75 poises at 100 F.ove1f1 a period of days for example being not unusual, and for this reason it is best in manufacture to apy proximate higher viscosities and visciditiesi in the ranges mentioned. If, on aging, the viscosity of the lubricant product drops too far, these values can be restored vby reheating the product or by repeating the oxidizing operation. The stability kof the lubricant product is dependent, largely if not entirely, upo'n thorough mixing of the several components of the composite product.

In some cases the stability of the lubricant product may be improved, if thorough mixing is not otherwise effect-ed, by passing the composite following the oxidizing operation through a grinding mill or dispersion mill. This treatment tends to involve an abnormal initial reduction in viscosity and viscidity and where it is used it is usually advantageous to bring the composite to a more viscuous and more viscid condition before subjecting it to this treatment.

The light lubricating oils useful in the composition of. the invention include the class comprising the light and medium oils commonly used for the lubrication of automobile internal combustion motors. The heavy flux oils useful in the composition of the invention include the class -comprising the residues produced in the distillation of crude petroleums for the manufacture of lubricating residues. LightV lubricating ticula'rly of the apparatus used for measuring ism 16 carr ing oils and heavy flux oils from Gulf Coast or Gulf Coast type'stocks and crudes are articularly advantageous as componentso Athe composition of the invention.

The caustic bottoms from the distillation or redistillaton of lubricating oils over caustic alkali, particularly lubricating oils from Gulf Coast or Gulf Coast type stocks or crudes, are particularly useful in the com'- position of the invention. These caustic bottoms include sodium soaps of petroleum, acids, probably' naphthenic acids, and very heavy lubricating oil constituents iny admixture; their eiiicacy is apparently due primarily to the particular soaps present enhanced, probably, by the associated lubricating oil constitutents. 111,.any event, these caustic bottoms are especially valuable as co o@ nents of the lubricant product of the inv ntion. Caustic bottoms containing sulpho'- nated or sulphated compounds such as are produced in the caustic treatment of oils following treatment with sulphuric acid, ap-

parently lack the quali/ties requisite for use the present invention. x

in the composition of The caustic bottoms first referred to above are those produced in the common practice "in the distillation of lubricating oils, par- Gulf Coast lubricating oils, in n which practicethe oils are not subjected to treatment with'sulphuric acid prior vto the 'treatment or distillation with caustic soda. Inthe accompanying drawings, Figs. 1' land 2 are front and side elevations, respectively, -of an," assembled instrument for measuring lKnopf viscidity and `Knopf adhesiveness, Fig. 3 is a fragmentary detail of the'apparatus used for measuring Knopf viscidity and Fig. 4 is ya fragmentary detail Knopf' adhesiveness.

The instrument illustrated in the drawings comprises a holder 10 for receiving and holding the viscidity test receptacle or the adhesiveness test receptacle, a plunger driving mechanism comprising a shaft l11 passing through gland 12 andjconnected to piston 13 within cylinder 14 and carrying a driving weight 1 5, and a Weighing mechanthe holder 10, all carried on a unitary rame 17. The opposite ends of the cylinder 14 are` connected by a pair of pipes 18 and 19, a gate valve 20 beingpro-l vided in pipe 18 and a needle valve 21 in pipe 19.' An open riser 22 isalso connected to the upper end of the cylinder 14. A catch 23 is provided for holding the plunger mechanism in a raised position. "The holder 10 lis of thermal insulating material to assist in maintaining the temperature-of samples constant during the test. y,

' In operation to determine the values either of viscidit or of adhesiveness as specified abovethe limiting rate of drop of the plunger mechanism, with the plunger or push rod 24 'in the holder 10, and theplunger mechanism,

i carrying "a plunger 24a With a flat circular head 1/2 in diameter and 1/16 thick carried by a shank 1/1 in diameter is released. As soon as the load imposed on the Weighing mechanism 16 by themotion of the plunger 24a through the lubricant reaches a substantially constant value, usually in 5-8 seconds after enterin theV lubricant, small weivhts equalling t is load are placed on the llarge weight 15. l A reading of the load on the weighin 'mechanism 16 is then taken as the plunger ead passes a point 1/2 above the center of the body ofthe lubricant and. .again when the plunger head asses a point` y2 below the center ofthe bo y of lubricant (see pointsA and B in Fig. 3) and these readings-are averaged to give the Knopf viscidity. In carrying out the Knopf adhesiveness test, a receptacle 26 and a plunger 34 are used. This receptacle comprises a cylinder with an accurately dimensioned bore 27 which is `.5/ in diameter, a vent opening 28 runf ning through the wall of the rece tacle'and communicating withl the ends o the bore through apertures29 and430, one end of the vent being enlarged to form a thermometer Well 31, and removable end members 32 andl 33 screwed 4into seats in the ends of the cylinder. This plunger has a body portion 7/8.1ong` and 0.003 less in diameter than 4the bore 27, an advancing end 1/8 long, the p l edge of which is tapered at 30 and an end adapted to contact with the pus rod 24o of spherical section on va 1/2 radius. TheA plunger 24a. usedin making the viscosity test may be used as the push rod 246 in making the adhesiveness test.-

n` carrying out the Knopfadhesiveness test, the receptacle 26 and the plunger 34 are chilled in achilling cup to the Standardtem perature of 0 F.,"Withdrawn from the chilllng cup and a film of the'lubricant tol be tested isappliedto the interior of the bore 27 and brought to a standard thickness of 0.003'by passin a sizing plunger 0.006 less in diameter t an'the bore therethrough, the plunger 34 is coated with the lubricant and inserted in the end of the bore 27 adjacent the seat for cover 32 with the advancing and in, the covers 32 and 33 screwed. in place, the assembled receptacle then replaced in the chilling cup and brought. to the standard temperature :of 0 F., Withdrawn' from the chilling cup-and inserted -in' the holderv 10 with the end of the bore containing the plun' ger 34 upv and the plunger mechanism released. As soon as the loadl imposedon the 1 weighing mechanism 16 by the motion ofthe plunger 34 through the borej27 reachesA a` substantially constant value, usually in 5-8 seconds after its motion beginslsmall weights equalling lthis load are placedy on the large` weight 15. A reading of the Iload imposed upon the weighing mechanism 16 is then 'asA .made asv the plunger passes two points adja.-

cent the midpoint of its travel through lthe bore (see points C and D in Fig.; 4) 'and thesev readings are. averaged \.to give' the Knopf adhesiveness.

We claim: i 1. An improved gear lubricant consisting essentially of an oxidized blend of light lubricating oil, heavy fiux oil and sodium- 'soaps .of petroleum acids substantially free from water, saidblend having` a Mac-Michael viscosity ojf -85 poises at 100 F. and a Knopf vviscidity not exceeding; 12 ounces at 0 F 2. .An improved gearrlubricant consisting essentially vof an oxidizedv blend of-light lubricating oil, heavy flux oil and sodium soaps of petroleum acids substantiadl'y 'free ,I

from water, said blend having a Mac hael 'viscosity of 55-100 poises at 100 F.v and a p Knopf viscidity not exceeding 12 ouncesat 3. improved gear lubricantconsisting essentially of an oxidizedlblend of light lubricating oil, heavy flux oil and sodium soaps of petroleum acids'substantially free from Water, said blend having a MacMichael viscosity of 70-85 poises at. 100 F., a Knopf W viscidity vnot exceeding 12 ounces at 0 F. and a `Knopf adhesiveness not exceeding 75 ounces at 0 F, 'f

4. Anv improved essentially of an oxidized blend of light Alubricating oil, heavyflux oil and sodium soaps of petroleum acids substantially free from water, said blend having aMacMichael viscosity of 55-100 poises at 100 F.,-a Knopf l-^viscidity not exceeding 12 .ounces at 0 F. .and a Knopf adhesivene'ssnot exceeding 75 ounces at OfF.`

5'. An improved gearlubricant consisting essentially of an oxidized 'blend of light lubricating'oil, heavy flux oil and caustic botover caustic soda,'said blendl being substantially free from waterand'having a`Ma'c- Michael viscosity of 70-.85 poises at 100 F. and a Kno f viscidity not exceeding' 12 ounces at0%`. i-

6.- An improved gear lubricant consisting essentially of an oxidized blend v-oflight-lu'- bricating.oil, .heavy flux oil. and caustic botgea-r lubricant 'consistingV ytoms from the distillation of lubricating oil toms from the distillation of lubricating oil over caustic soda, said blend being substantially freevfrom water and having a Mac- Michael viscosity of 55-100 poises at 100 F. and a Knopf viscidity not exceeding 12 ounces at 0 F. v

' 7. An improved gear lubricant consisting essentially of an oxidized blend of light lubricating oil, heavy iiux oil and caustic bottoms from the distillation-'of lubricating oil over caustic soda, said blend being substantially free from Water and having a Mac- Michael viscosity of 7 0-8q5 poises at 100 F., a Knopf viscidity not exceeding 12 ounces at 0 F. and Knopf adhesiveness notexceeding 75 ounces at 0 F.

8. An improved gear lubricant consisting essentially of an oxidized blend of light lubricating oil, from the distillation of lubricating oil over caustic soda, said blend being substantially free from water and having a MacMichael viscosity of 55-100 cises at 100 F., a Knopf viscidity not excee ing 12 ouncesat 0 F. and a Knopf -adhesiveness not exceeding 7 5 ounces at 0 F.

9. An improved gear'lubricant consisting essentially of an oxidized blend substantially free'from Water of about one-half light lubricating oil, about one-third heavy liux oil and about one-sixth caustic bottoms from the disc tillation of lubricating oil over caustic soda.

i mixture of light 10. An improved gear lubricant consisting essentially of an oxidized blend substantially free from water of about ve-sixths ofa lubricating oil and heavy flux oil having a Saybolt viscosity of -62 seconds at 210 F. and about one-sixth caustic bottoms fromthe distillation of lubricating oil over caustic soda.

11. An improved gear lubricant consisting essentiallyof an oxidized blend 'of a mixture of light lubricating oil and heavy, iux oil having a Saybolt viscosity of 55-62 seconds at 210 F. and caustic bottoms from the distillation of lubricating oil over caustic soda,

said blend being substantially free from water and having a MacMichael viscosity 4of -85 poises at 100 F. and a AKnopf viscidity -not exceeding 12 ounces at 0 F. l

12. An improved gear lubricant consisting essentially of an oxidized blend of a mixture of light lubricating oil and heavy iiux oil having a Saybolt viscosity of 55-62 seconds at 210 F. and caustic bottoms from the dis.

tillation of lubricating oil over caustic soda, said blend being substantially free from water and having a MacMichael viscosity of 55-100 poises at 100 F. and a Knopf viscidity not exceeding 12 ounces at 0 F.

13. An improved ear lubricant'consisting essentially of an oxidized blend substantiallyr free from water of 83-85% of a mixture of light lubricating oil and heavy flux oil having a Saybolt viscosity of 55-62 seconds at cating oil, heavy heavy flux oil and caustic bottoms 210 F. and 15-17% of caustic bottoms from' the distillation of lubricating oil over caustic soda having a Knopf viscidity of 15'35 ounces at 100 F.

' 14. An improved gear lubricant consisting essentially of an oxidized blend substantially free from Water of (S5-88% of amixture of light lubricating oil and heavy flux oil having av Saybolt viscosity of 55-62 seconds at 210 F. and 12-35% of distillation of lubricating oil over. caustic soda having a Knopf viscidity of 15-35 ounces at 100 F. y

15. Animproved gearlubricant consisting essentially of an oxidized blend kof light lubriiux oil and causticbottoms from the distillation of Gulf Coast type lubricating oil over caustic soda, said blend beaia-100 F. and a Knopf viscidity not exceeding 12 ounces at 0 F. c 16. An improved gear lubricant consisting essentially of an oxidized blend of light lubri'- cating oil, heavy liux oil and caustic bottoms from the distillation of Gulf Coastl type lubricating oil over caustic soda, said blend being substantially free from Water and having a MacMichael viscosity of 55-100 poises at 100 F. and a Knopf viscidity not exceeding 12 ounces at 0 F. 17. An improved gear lubricant ing essentially of an oxidized blend o alight lubricating oil, heavy bottoms from the distillation of Gulf Coast type lubricatingsoil over caustic soda, sai blend beingsu and having a MacMichael vviscosity of 7 0-85 poises at 100 F., and a Knopf viscidity not exceeding 12 vounces at 0 F. and a Knopf adhesiveness not exceeding ounces at 0 F. 18. Anim roved gear lubricant consisting essentially o an oxidized blend of light lubricating oil, heavy flux oil and caustic bottoms from the distillation of Gulf Coast type lubricating o1l over caustic soda, said blend befree from water of about one-half light lub?A ricating oil, about one-third heavy flux oil and about one-sixth caustic bottoms from the distillation of Gulf Coast type lubricating oil over caustic soda.

20. An improved gear lubricant consisting;

essentially of an oxidized blend substantially free from Water of about five-sixths of a mix'- ture of light lubricating oil and heavy flux oil having a Saybolt viscosityof 55-62 seconds at 210 F. and about one-sixth caustic' caustic bottoms from the iiux oil and caustictantially free from Water a Knopf viscidity not exceeding 12 f .psg

Sliy

nsistbottoms from the distillation of type lubricating oil over caustic soda.

21. An improved ear lubricant consisting essentiall of anv oxi of light ubricating Voil and heavy ilux oil having a Sayboltv1scosity of 55-62 seconds at 210F. and caustic bottoms from the disu tillation of Gulf Coast type lubricating oil over caustic soda, tially freeV from Michael viscosity of 70-85' poises at 100 F.' and a Knopf viscidity notexceeding 12 ounces at 0 F.

22. Anim roved said blend being substanan oxidized blend of a mixture of light icating oil and heavy liux oil having a Saybolt viscosity of 55-62 seconds `oil with at 210 F. and caustic bottoms from the distillation of Gulf Coast type lubricating oil over caustic soda, tiall free from water and havinga Mac- Mic nel-viscosity of -100 poises at .100 F. and a -Knopf viscidity` ounces at 0 F.

23. An improved essentially of an oxi ized blend substantially free from water. of 88% of a mixture of light lubricating oil and heavyviux oil hav- 1 ing a Saybolt viscosit .of 55-62 .seconds at 210 F. and 1235% :o caustic bottoms from the distillation of Gulf Coast typelubricating oil over caustic soda.

24. A'method of ricant comprising mixing a light lu a hea mixture to a lfree incorporating sodium soaps of 'petroleum acids in this-mixture and, 'after incorporation of the said soaps, blowing the composite ricating flux oil `and heating the with dry air at a temperature approximating y 25. A method of ,compounding a ear lubricant comprising mixing a light lu ricating a heav mixture to a free incorporating caustic bottoms from the distillation of ubricatingloil in this mixture and, after incorporation of the said caustic flux oil and heating the Gulf Coast l ized blend of a mixture.

water and having a Macearlubricant consisting said blend being substannot exceeding 12 ear lubricant consisting compounding a ear lub-4 i y fluid condition, thereaftery fluid condition, thereafter bottoms, blowing the composite with drly airl at a temperature approximating 300 In testimony tures. f

CARL L. KNOPF.

STANLEY D. 

